Hopefully new question on an old topic (mast foam drilling)

[taylormade]

So if you've been following my saga, the I picked up over a year ago had a mast that had been cut 4-5' short and the sails were also "trimmed" to accommodate. I found a Hobie Cat 18 mast locally on CL, picked it up and I also picked up another, broken mast off an with all the hardware in tact for spares. Sweet!

I planned on running wires all over the new mast. I wanted an anchor, steaming, and spreader bar lights to name a few. Getting the caps off the sealed Hobie mast was quite a challenge, but when I finally was able to, I found that there was foam inside. I understand the practice of sawing PVC to create a drill bit but what's the practice for "dropping off wires" halfway up the mast?

I suppose I could lay the PVC pipe next to the mast and mark where I wanted the wires to be on the mast and then drill holes in the pvc, prewire the PVC with the wires sticking out of the holes I drilled in the PVC and then drill holes in the mast big enough to be able to get needle nose pliers in to pull the wires out? I'd have to get some grommets for the mast and then silicone around the wires to try to seal the holes.

Am I overthinking this or underthinking it?

[Russ]

So does the Hobie mast have foam all the way through? That would suck.

If so, I guess you need to "drill" all the way through the mast.

Then, I guess you would "drill" horizontally into this new shaft. It's gonna be difficult. Maybe run a pilot string from the bottom up to the horizontal hole and fish it through.

You will have to be creative.

[taylormade]

So does the Hobie mast have foam all the way through? That would suck.

If so, I guess you need to "drill" all the way through the mast.

Then, I guess you would "drill" horizontally into this new shaft. It's gonna be difficult. Maybe run a pilot string from the bottom up to the horizontal hole and fish it through.

You will have to be creative.

No, thankfully it doesn't go all the way through... so far it's just small sections.

[Russ]

I think you are going to have to just be creative. I thought I'd pull the steaming light through easily. No such luck. Ended up pulling it down to the base where I soldered it into the existing pairs.

Remember, LEDs are polarity sensitive. So you can use 2 wires for 2 fixtures. Just reverse the polarity.

[taylormade]

I think you are going to have to just be creative. I thought I'd pull the steaming light through easily. No such luck. Ended up pulling it down to the base where I soldered it into the existing pairs.

Remember, LEDs are polarity sensitive. So you can use 2 wires for 2 fixtures. Just reverse the polarity.

I think I have an idea of what I'm going to do. I'll take pics and add it to this thread as either a cautionary tale or a humble brag. As for the LEDs, that'd be great except I'm doing different switches for different lights. All can share the ground but the positive will need to be separate.

Thanks for the responses.

[Tomfoolery]

I just added an anchor light to the top of the mast, but I ran the wiring all the way to the base. I was going to join the wiring for the masthead (steaming) light and anchor light right at the masthead light, but the stainless mounting base for that light is riveted onto the mast, and I couldn't get my fingers or a wrench behind it to hold the nuts holding the light to it. I didn't feel like drilling them out and so on, so I snaked the wire all the way instead. And besides, having them joined at the base, where I can pull the connection out to repair if needed, is an advantage.

The anchor light is an LED, but it has a full-wave type rectifier built into it (it will light regardless of the source polarity), so I used diodes for both lights and a 2P2T marine toggle to switch polarity on the existing wiring and light one or the other as desired. Panel label is simply 'mast light'. If the plug/socket combo wasn't polarized, which many aren't, I could just pull the plug and put it in the other way, and I believe some folks here do that.

I also used zip ties every couple of feet, and left the tails on them, to keep the wire rattling down.

[Russ]

The anchor light is an LED, but it has a full-wave type rectifier built into it (it will light regardless of the source polarity), so I used diodes for both lights and a 2P2T marine toggle to switch polarity on the existing wiring and light one or the other as desired. Panel label is simply 'mast light'. If the plug/socket combo wasn't polarized, which many aren't, I could just pull the plug and put it in the other way, and I believe some folks here do that.

I had the same issue with the (what did you call it? Rectifier?) the anchor light didn't care about polarity. So I put a diode inline that did care about polarity.

I also have a "Mast Light" switch on the panel and then a DPDT toggle to switch polarity at the panel to select anchor/steaming. Saved me an extra wire, but more importantly, an extra deck fitting and run back to the panel. I used stock wiring.

Now if I wanted spreader lights or some such thing, I'd have to run another pair up there. VHF is on top. I pulled a string through in case I want another pull in the future.

[The Mutt]

I bought some PVC pipe and cut teeth on one end similar to a hole saw using a Dremel, it took about an hour to cut through the foam inside 'Imagines' mast, when needed I glued a second section of PVC pipe to the first, when I was all the way through I used the compressor to blow out the cut foam from inside the tube, cut off the saw end and extra length of pipe from the top, shot a string line down the tube again using the compressor, when I pulled the television antenna wire through the tube I also pulled a new string line that I tied off on top and bottom of the mast in-case I need to run any more wires.

Fair Winds
Glenn

[1st Sail]

I did the same thing. Made a toothed hole saw from a pvc coupler then inverted the mast with the track up hoping gravity gravity would help the pvc drill track on the forward side of the mast when drilled. I ran into a lot of mixed foam densities and had to continue withdrawing the pipe and push the foam out with a fish tape. Some times I could could not drill more than 1-2 in. before the foam jammed inside the pvc.

FYI I used pvc water pipe vs. pvc conduit as the ID of water pipe is considerably larger and PVC water compared to pvc conduit weighs considerably less.

[Tomfoolery]

The anchor light is an LED, but it has a full-wave type rectifier built into it (it will light regardless of the source polarity), so I used diodes for both lights and a 2P2T marine toggle to switch polarity on the existing wiring and light one or the other as desired. Panel label is simply 'mast light'. If the plug/socket combo wasn't polarized, which many aren't, I could just pull the plug and put it in the other way, and I believe some folks here do that.

I had the same issue with the (what did you call it? Rectifier?) the anchor light didn't care about polarity. So I put a diode inline that did care about polarity.

I also have a "Mast Light" switch on the panel and then a DPDT toggle to switch polarity at the panel to select anchor/steaming. Saved me an extra wire, but more importantly, an extra deck fitting and run back to the panel. I used stock wiring.

The rectifier I'm referring to is just a simple grouping of four diodes will allow an alternating input current (like the AC in your house) to only flow in one direction through the load. But if you feed it direct current, it will still flow in only one direction through the load, but the polarity of the source current won't matter. The Dr. LED bulb I have in my anchor light has four diodes (visible, and actually marked D1 through D4) built into it, along with other circuitry to control voltage and current through the LED elements, so it will light no matter the source polarity.

If you connected it to an AC power supply, it would still light, but blink at 120Hz (in North America, on 60Hz power), which would explain why LED light strings used for outdoor decoration have that annoying rapid-blink effect that incandescent bulbs don't have (they can't cool down fast enough to go dark when the voltage is crossing the zero point).



So it's not that you need to rectify AC power for a nav light on a boat, but some bulbs, like my anchor light bulb, have a rectifier built in and so a separate diode has to be used to control (via source polarity) whether the bulb gets power or not, just like if it was an incandescent bulb.